Timer-brush



E. L. MILLER.

TIMER BRUSH.

APPLICATION FILED JAN. 14. l9l9.

Patented May 10,1921

I ahvzw toz EanZQL,/V,c'ller UNITED STATES EARL L. MILLER, 01 OVERBROOK, KANSAS.

TIMER-BRUSH.

Specification of Letters Patent.

Patented May 10, 1921.

Application filed January 14, .1919. Serial No. 271,035.

manufactured at a minimum cost; to pro-' tract the life of the device; and to obtain the most efficient contact, while minimizing the danger of injury to the brush from back firing.

I have herein described and explained the best embodiment of my invention at present a a known to me,1nd1cat1ng 1n my claims the scope and essentials of the invention in its various phases and aspects.

In the accompanying drawings, I have shown the invention-as embodied in a form which is most economical of construction, and which insures the attainment of all the other desired objects above mentioned.

In this embodiment the invention comprehends as driving element for the brush a sleeve which is preferably bent into cylindrical. form, and which is provided with a longitudinally arranged diametrically extending flange, which, in this instance, is integral with the sleeve, being formed by bending the end of the material of which the sleeve is formed, outwardly This sleeve is provided with a spring contact arm,extending therefrom in a substantially spiral direction, and having at its outer or free end a hardened metal contact element. The flange just mentioned is slotted longitudinally to provide restraining means for'the spring arm, which means prevents any substantial transverse bending or shifting of said arm, and also limits the movement thereof in a radial direction.

In the most complete embodiment of the invention, (as herein shown), an auxiliary extended sustaining element is provided, ar-

ranged parallel to, but independent of, the

spring arm, for a substantial distance along the outer face of the latter. As shown herein, this auxiliary element is preferably resilient, and is itself controlled by the restraining means just described.

In the drawings, Figure I, is a plan view of a timer equipped with my improved contactbrush.

Fig. II, is a detail perspective View of the brush member itself, in this instance, in its preferred form.

Referring to the drawings, the timer casmg is indlcated at 10, the contact segments at 11, and the conductor terminals at 12. These may be of the usual or any preferred construction: As shown,the timer casing 10 and its associated parts 11, 12, etc., are of the familiar form heretofore used on Ford automobiles. The timer shaft is shown at 13, and is revolved in the ordinary manner. Said shaft is cylindrical, as shown,

and is adapted to receive and rotate the brush which constitutes the present invention. This brush includes as driving element a sleeve 14, of novel construction, being preferably formed from a strip of sheet 'metal bent into cylindrical shape, and of a size to fit the shaft 13. In this embodiment of the lnvention, one end of the strip is bent and extends outwardly from the sleeve to provide an elongated radially disposed flange 15, which is provided with a slot 16. A spring arm 18 is mounted on and extends from the round sleeve, being, in this instance, attached or secured to the sleeve against its rounded surface through the medium of a rivet 17, or other fastening device, at one extremity of said arm. The resiliently flexible spring contact'arm 18 diverges tangentially from the rounded surface of the sleeve 14, against which it is mounted, and extends on outward from and around the sleeve, preferably in a sort of curving, spiral fashion, as already noted. The tangential divergence of the spring arm 18 permits it to flex easily and smoothly to and from and against the rounded surface of the sleeve 14:, without sharply localized stress or strain. In Fig- I of the drawing, the arm 18 is shown flexed against the round sleeve from the point of attachment of said arm at 17 around to the point of divergence thereof over a substantial distance. The diverging spring arm 18, passes freely through the slot, at either edge of the arm, 16, in the flange 15, the metal at the ends thereof preventing any substantial transverse, shifting of the play of the arm in a radial direction. The arm 18 extends on outward from and around the sleeve let so as to come into approximately tangential relation to the surface of the cooperating timer casing 10, and has se cured thereto at its free end a hardened metal contact element or wiper 19, which is adapted to engage the inner surface of the casing 10 and wipe over the segments 11, in the usual manner. The auxiliary sustaining element 20, (in this instance a leaf spring), lies outside of and parallel to the arm 18 in contact with but independent of the arm and extends around the sleeve 14 along the outer face of said arm throughout an extended portion of the length thereof in the region of its contact with and divergence from said sleeve, said element being secured to the sleeve 14;, preferably by the fastening device 17, which, in this instance, secures the arm to the sleeve. The depth of the slot 16, in a radial direction, is preferably sufficient to allow some radial play of the arm 18, even when the auxiliary sustaining element 20, is employed. The sleeve 14:, is provided with a notch 21, for the reception of the pin 22, carried by the shaft 13, whichserves as means for removably securing the sleeve upon the shaft.

It will be noted that the spring arm 18, at its inner extremity, extends from, or is rigidly or fixedly attached to, the sleeve, but that the restraining means (in"this instance the slotted flange) carried by the sleeve, is located at some distance from the region of rigid extension, or rigid attachment, of the arm with relation to the sleeve, and does not constitute an absolutely rigid connection. This organization minimizes the tendency to crystallize, which is manifested by the spring arm, at, or near, the region where it extends from or is rigidly attached to, the sleeve. The employment of the auxiliary sustaining element 20 carried by the sleeve enhances this desirable feature and also prevents the buckling of the main spring arm, when back firing occurs. This element 20 acts, in a word, to ease, diffuse, and control the variations of stress and strain in the contact arm 18.

It will also be noted that the slot 16,0f the restraining device for the arm 18, is,

in the instance shown, completely inclosed,

so as to extend across the entire width of the arm 18, and, in the complete embodiment,

varied, as it is only necessary for the restraining device to overlie, overhang, or engage a suflicient portion of the spring arm to insure the proper limitation of the play in a radial direction. Furthermore, in the instance shown; the restraining device is, for reasons of economy,'formed integral with the sleeve, and the arm 18, is shown as of bumps and hollows.

non-integral with the sleeve. These and other details, however, may be varied, without departing from the spirit of the invention.

The invention as shown and described, provides an exceedingly efficient and inexpensive timer brush which may be readily secured to or removed from the timer shaft, permitting a broken or damaged brush to be replaced at a nominal cost.

v I have above referred to the use of my invention on automobiles for the reason that it is of the greatest advantage in this field of use. For instance, the timer brush heretofore employed on one widely used type of car had for its contact 'arm a heavy pivoted lever with a roller contact element at one end urged into contact with the timer easing by a. helical tension spring acting on the other end of the lever. This contact arm did not maintain continuous, uniform contact with the interior of the timer casing, but would lose and regain contact from time to time (owing to its own inertia, and the vibration of the engine and ofthe vehicle) in such a way as to hammer and wear the inner surface of the easing into a succession This condition of the casing still further accentuated the maloperation that gave rise to it, and made the sparking action of the timer most irregular and unsatisfactory. I

With its light, flexibly resilient Spring contact arm, my timer brush not only maintains contlnuous good, firm, even contact with the timer casing,without danger of hammering or injury thereof,but even acts to smooth out and restore to operating efficiency a timer casing that has been more or less ruined by a brush of the old type. This maintenance of firm contact by my brush is due to the easy, smooth flexure of the spring arm 18 to, from, and against the rounded surface'of the driving element 14, which not only tends of itself to minimize breakage through fatigue crystallization of the metal (even without the restraining means at 16), but also facilitates the maintenance of adequatecontact pressure between contact 19 and timer casing 10 with a substantially tangential relation of brush arm and easing. This latter relation is of importanceto smooth, continuous contact and uniform sparking,ias well as to the avoidance of buckling of the arm and injury to the casing surface when backfire occurs,- quite apart, again, from the effect of the sustaining and restraining elements 20 and 16 in this respect,

The invention is susceptible of various changes in its form and proportions and minor details of construction, and the right is herein reserved to make such changes as properly fall within the scope of the appended claims.

contact segments of a timer casing;

restraining outward movement of the porg from and around tion of said arm extendin said driving element.

2. A timer brush comprising a sleeve; a spring arm rigidly connected to and extending from said sleeve; and restraining means also extending from the sleeve for freely engaging said arm, to limit the radial play thereof, at a distance from the region of rigid connection between the arm and the sleeve.

3. A timerbrush comprising a sleeve; a spring arm extending from said sleeve, and having its outer end disposed for contact with the contact segments of a timer casing; and restaining means carried by the sleeve, said means freely overhanging the arm and being adapted to limit the radial play thereof, and to prevent substantial transverse shifting of the arm.

. 4. A timer brush comprising a sheet metal sleeve with integral overhanging restraining means in longitudinal flange form extending outward therefrom; and a spring arm extending from said sleeve within said overhanging restraining means, and having its outer end disposed for contact with the contact segments of a timer casing.

5. A timer brush comprising a sleeve; a spring arm for making contact with the contact segments of a timer casing attached to to said sleeve; and restraining means for said arm extending outward from said sleeve at either edge of said arm, and also overhanging the latter at either edge thereof.

6. A timer brush comprising a sleeve with a restraining portion affording a slot extending lengthwise of the sleeve and overhung by said portion; and a spring arm extending from said sleeve through said slot and having its outer end disposed for contact with the contact segments of a timer casing.

7. A timer brush comprising a strip of metal in the form of a non-continuous sleeve with an integral longitudinally radial flange extending outward at one end of the strip, said flange being provided with a longitudinal slot; and a spring arm rigidly connected with the sleeve and extending through said slot, said arm having its outer extremity disposed for contact with the contact segments of a timer casing.

8. A timer brush comprising a sleeve; a spring arm extending from said sleeve; and an elongated auxiliary sustaining element part for engagement with such casing;

for said arm extending from said sleeve in the same direction as said arm.

9. A timer brushcomprising a sleeve; a spring arm extending from said sleeve; and an elongated auxiliary sustaining spring extending parallel to and outside of said arm.

10. A timer brush comprising a sleeve; a

spring arm extending from said sleeve; an

elongated auxiliary supporting element ex tending in contact with said arm; and restraining means for said arm and said auxiliary element carried by the sleeve, butindependent of the main connection between the sleeve and the auxiliary element.

11. Atimer brush comprising a strip of metal in the form of a non-continuous sleeve with an integral longitudinally radial flange extending outward at one end of the strip, said flange having a longitudinal slot; a spring arm rigidly extending from the sleeve and passing through said slot, the outer extremity of said arm being disposed for contact with the segments of a timer casing; and an auxiliary spring secured to the sleeve and also extending through said slot.

12. A timer brush comprising a round driving element; and a resiliently flexible spring arm mounted against the rounded surface of said element diverging and extending therefrom tangentially and spirally outward around the element, so as to flex easily and smoothly to and from and against said rounded surface, without sharply localized stress or strain.

13. A' timer brush comprising around driving element; and a resiliently flexible spring arm mounted on said element diverging tangentially from its rounded surface and extending outward from and around the element so as to come into approximately tangential relation to the surface of a cooperating timer casing, and having a contact so that said spring arm shall flex easily and smoothly to and from and against the rounded surface of said element without sharply localized stress or strain, and that said contact part shall maintain continuous good contact with said casing without danger of hammering or buckling.

14;. A timer brush comprising a round driving element; a resiliently flexible spring arm mounted on said element diverging tangentially from its rounded surface and extending from and around the element, so as against tending from and around the element, so as to flex easily and smoothly to and from and against said rounded surface; an auxiliary resilient sustaining element for said spring arm carried by said driving element and extending around the same along the face of said spring arm in the region of its contact with and divergence from the driving element; and means carried by said driving element for restraining radial movement of the portion of said spring arm extending from sald drlving element.

In testimony whereof I aflix my signature.

EARL L. MILLER. 

